Enteric glia and visceral pain

摘要 腹痛是最常见的胃肠道问题，也是功能性腹痛的主要原因。 胃肠道疾病，如肠易激综合征(IBS)和炎症性肠病(IBD)。 尽管作出了广泛的努力，但对于负责生产的机制仍然没有达成共识。 腹痛。这种缺乏进展的情况反映在当前治疗方法的效果不佳和停滞不前 腹痛新的靶向治疗方法的进展。这项建议的总体目标是理解 使内脏神经纤维敏化的机制，这一提议的具体焦点是机制 受肠道神经胶质细胞的调节。神经胶质细胞在中枢神经痛觉传递的调节中起核心作用 系统，但神经胶质细胞和神经纤维之间的相互作用如何在肠道中促进 内脏疼痛是未知的。这一提议检验了肠神经胶质细胞对内脏的贡献这一中心假说。 通过与伤害性感受器直接相互作用和间接调节免疫反应而产生的超敏反应。这 双重假设将在两个特定的目标上进行测试，这两个目标利用靶向遗传模型来操纵胶质细胞， 已建立的内脏高敏感性动物模型，光遗传记录，免疫组织化学 分析、电生理学和内脏运动反射记录，以研究对感觉神经元活动的影响。 健康和疾病。目标1将验证肠神经胶质细胞直接调节内脏活动的假设 痛觉感受器。特定目标1a将使用化学发生和基因敲除小鼠模型来研究 神经胶质递质释放和特异性靶点1b将使用选择性药物和基因敲除小鼠来研究神经胶质细胞的作用 调节三磷酸腺苷和组胺供应的胞外酶。目标2将检验肠上皮神经胶质细胞 通过与免疫细胞的相互作用间接调节内脏伤害性感受器。特定目标2a将使用 转基因小鼠和单抗研究神经胶质细胞与巨噬细胞的相互作用 释放介质，包括三磷酸腺苷和巨噬细胞集落刺激因子。特定目标2b将使用基因敲除小鼠和单抗 用于研究二次依赖于胶质细胞和淋巴细胞之间相互作用的抗体 通过抗原提呈来调节。AIM 2中的免疫反应将通过微阵列进行分析， 免疫组织化学和流式细胞术。这项研究的结果将确定神经胶质免疫的新作用。 外周感觉神经元的相互作用。这一对内脏敏化机制的新见解 神经将促进功能性胃肠道腹痛新疗法的发展 疾病，如IBS和IBD。

ABSTRACT Abdominal pain is the most common gastrointestinal issue and is a major cause of suffering in functional gastrointestinal disorder such as irritable bowel syndrome (IBS) and in the inflammatory bowel diseases (IBD). Despite extensive efforts, there is still no consensus regarding the mechanisms responsible for producing abdominal pain. This lack of progress is reflected by the poor efficacy of current therapies and the stalled progress toward novel, targeted therapies for abdominal pain. The overall goal of this proposal is to understand mechanisms that sensitize visceral nerve fibers and the specific focus of this proposal is on mechanisms regulated by enteric glia. Glia play a central role in the regulation of pain transmission in the central nervous system, but how interactions between glia and nerve fibers in the intestine contribute to the generation of visceral pain is unknown. This proposal tests the central hypothesis that enteric glia contribute to visceral hypersensitivity by direct interactions with nociceptors, and indirectly by modulating immune responses. This dual hypothesis will be tested in two specific aims that utilize targeted genetic models to manipulate glia, established animal models of visceral hypersensitivity, and optogenetic recordings, immunohistochemical assays, electrophysiology, and visceromotor reflex recordings to study the impact on sensory neuron activity in health and disease. Aim 1 will test the hypothesis that enteric glia directly modulate the activity of visceral nociceptors. Specific Aim 1a will use chemogenetic and knockout mouse models to study the role of gliotransmitter release and Specific Aim 1b will use selective drugs and knockout mice to study the role of glial ectoenzymes that regulate ATP and histamine availability. Aim 2 will test the hypothesis that enteric glia indirectly modulate visceral nociceptors through interactions with immune cells. Specific Aim 2a will use transgenic mice and monoclonal antibodies to study glial interactions with macrophages mediated by the release of mediators including ATP and M-CSF. Specific Aim 2b will use knockout mice and monoclonal antibodies to study interactions that are secondarily dependent on interactions between glia and lymphocytes mediated by antigen presentation. Immune responses in Aim 2 will be analyzed by microarrays, immunohistochemistry, and flow cytometry. The results of this study will identify novel effects of glial–immune interactions on sensory neurons in the periphery. This new insight into mechanisms that sensitize visceral nerves will facilitate the development of new therapies for abdominal pain in functional gastrointestinal disorders, such as IBS and IBD.